Christ alone accomplished our salvation. He did this by his perfect life (active obedience) and His substitutionary death (passive obedience). Jesus Christ’s death on the cross is our only source of forgiveness, life, and salvation.
So let our cry continually be sola Scriptura—Scripture is sufficient. And it is sufficient because it is God breathed. It is sufficient because it is God’s Word that does not return to Him empty, but always accomplishes the purpose for which He sends it. It is sufficient because it is the Spirit-filled and life-giving Word of God.
Faith in Christ is sufficient for salvation because Christ’s atoning work is sufficient. For we confess that we cannot be justified before God by our own strength, merits, or works but are freely justified for Christ’s sake through faith when we believe that we are received into God’s favor and that our sins are forgiven on account of Christ, who by His death made satisfaction for our sins. This faith God reckons to us as righteousness. Thus we receive the righteousness of Christ are seen as righteous in God’s sight by faith, by trust in Christ’s atoning work. We are saved and forgiven on account of Christ and we receive this by faith alone.
When we speak of grace, we must first ask the question: What is grace? Grace is God’s undeserved favor toward sinners. Grace is God’s unmerited good intention, His loving disposition toward those who have gone astray and are dead in sin and by nature children of wrath (Eph 2:1, 3). Grace, then, is something that resides in God and not in man.